BIOL220W Final Flashcards
Describe why temperature and precipitation vary globally and why some, but not all, portions of our planet show seasonality in temperature and precipitation
Regions near the equation have more direct sunlight year-round. Areas farther from the equator experience more pronounced seasons due to the 23.5 rotational tilt.
Explain how the variation in temperature, precipitation, atmospheric circulations, and/or seasons causes predictable global patterns in climate and distribution of organisms
Different regions with distinct climates support different types of life due to the specific challenges posed by their temperature, rainfall, and seasonal changes
Predict regional wet and dry seasons using your understanding of how/why atmospheric circulation patterns shift as the earth rotates around the sun
Hadley cells affect prevailing winds, which makes intense solar radiation equator, then rises, makes dry air, and returns to equator. During Summer, the sun rays are more direct
Explain the effect of prevailing winds and mountains on regional climate
Rain Shadow Effect: Rising moist air cools, then descending dry air absorbs moisture (Rain comes up a mountain, then peaks, then dry air warms as it goes down the mountain causing a rain shadow and making warm/dry air)
Describe 1-2 key features that make each biome unique
Average annual temp
Average total precipitation
Describe predicted (and already being observed) effects of climate change on the environment and how these changes might affect species interactions and distributions
Coral bleaching (overexposure to sun, temp change, pollution). Algae leaves the coral, so coral turns white and dies.
Also, air pollution, more asthma. Extreme heat, more heat strokes
Northern hemisphere has warmest temps when
June to August (wet season)
Southern hemisphere has warmest temps when
December to February (wet season)
Describe how species accumulation curves are generated and determine if all species have been counted in a community by interpreting species accumulation curve data
Developed by progressively sampling a community. As new species are taken, curve grows rapidly until curve plateaus over time.
Compare/contrast alpha, beta, and gamma species diversity concepts
Alpha-> species diversity within a single ecosytem, count # of species (species richness)
Beta-> Variation in species composition between different habitats
Gamma-> Total diversity at a regional scale, integrating both alpha and beta diversity
If alpha increases,
species richness increases
If beta increases,
communities have fewer shared species
Distinguish between two components of population abundance: size and density
Species density: Number of individual species in a given area
Abundance is number of individuals of species
Describe how population abundance data is collected and make some basic calculations using quadrat or mark-recapture data to estimate population size
To estimate population size, use area based survey (density) or
Line-transect survey (abundance) -> Sampling along a line (such as 20m, indiv. are counted as one moves along a line)
Mark-recapture survey (abundance)-> Used for mobile organisms (captured, marked, released)
Human population census surveys (both)
Quadrat
Sampling area of specific size. Individuals are usually counted in several quadrats
Explain the factors that directly determine population size (BIDE) and how they affect it
B= # of births
I = # of immigrant
D = Death
E = Emigrants
Life table needs age, # individuals in age class, survivorship, and fecundity (mean # of daughters)
Describe demography, including what can be calculated about populations and how it can be used in real life
Statistical study of populations; size, structure, distribution and changes
It can be used for conservation planning, endangered species, and pest/disease management
Compare/contrast the life history characteristics of populations described by the three forms of survivorship curves
Type I: most survive to old age
Type II: Chance of surviving remains constant during lifetime
Type III: High death rates for young, those that reach adulthood survive well
Infer whether a population is increasing, decreasing, or stable from its age structure distribution
Population growth (R) = B-D
Per capita growth rate (r) = (B/N) - (D/N)
Age structure diagram shows proportion of population in each age class
Interpret a cohort life table and calculate parameters (lx, bx, nx, no, mx) using provided ecological data
x=Age
nx= # of individual at age x
lx= survivorship: proportion of individuals that survive from birth (n0) at age x
mx= fecundity
lx= (nx/n0)
mx= (bx/nx) with bx= # born in between age classes
Calculate the net reproductive rate (R0), mean generation time (T), and growth rate (r) of a population using data from survivorship and fecundity and describe what the biological meaning is for each calculated value
R0= Average # of female offspring in a generation
T= Avg time from the birth of a female until the birth of her daughters
Population growth rate (r) = ln(R0)/ G
Net reproductive rate (R0) = sum(lxmx) .
Compare and contrast geometric and exponential growth models, including the relationship between lambda and r
Geometric -> 1 reproductive event per time period
Exponential -> Continuous, overlapping reproductive events
r= intrinsic growth rate
r=ln(lamba)
Predict population size: Nt=N0e^(rt)
For each generation, population size changes by a constant ratio
R0 is lamba in geometric growth models
R0-# of offspring per generation
Describe the meaning of the components (e.g., r, Nt) in growth model equations and use them in calculations
FOR EXPONENTIAL (instantaneous rate of change in pop size)
dN/dt = rN
r= b-d
Resources unlimited, thus per capita rate of change in pop. size = intrinsic growth rate
Describe why the incorporation of a carrying capacity (K) into the exponential equation changes the population growth curve to be logistic: consider this from mathematical and biological perspectives
Logistic is restricted because the carrying capacity is a restriction on the population count
Compare/contrast instantaneous and per capita growth rates vs. N for exponential and logistic growth models
dn/dt= instaneous rate of change in pop size
dn/DtN = per capita rate of change in pop. size (logistic)
Contrast how density-dependent and independent factors differ in their effects on population growth
Cause birth/death rates to increase based on population density (shelter, food, encountering mates) (DENSITY-DEPENDENT FACTORS)
Affect birth and death rates independent of pop. size (earthquake, storm, tsunami) (INDEPENDENT FACTORS)
Determine the effect of population size relative to K on per capita growth rate
Per capita growth rate decreases as pop size (N) approaches K
This growth rate is dependent on density
Estimate K using either instantaneous or per capita growth rates
K can change if environment changes
Populations live in ecosystems with other populations that may eat them or compete with them
The earth’s shape affects…
warming
Since temp is highest at the equator, solar radiation is
most condensed at equator
If earth tilt increases,
More pronounced seasons
Spring and fall equinox is when
both northern and southern hemispheres are same distance from sun
Hadley cells
Radiation warms surface at equator
Moist, warm air rises
Air cools + condenses (30 N & S)
Dry air moves toward equator
Ferrel cells
Between polar and hadley cells
Moist air rises at 60, condenses, and flows towards equator
At 30, cool dry air descends
Cool air travels back towards 60, taking moisture from surface
Polar cells
Near poles
Warm, moist air rises at 60, condenses
Dry, cool air flows toward poles, then descends
Dry desert at
30
Wet/humid at
60
Tropical climates near….Drier at….
Equator…. poles
Wind patterns are created by
3 cell types
Growing season is when
temp is above 0 Celcius
If precipitation goes below temp line, the
yellow is insufficient precipitation
A flatter slope on a rank abundance curve indicates
more species evennessM
Less in common between 2 communities
Higher b diversity
G
mean generation time (average time from the birth of a female to the birth of her daughters)
R0
Net reproductive rate= average number of female offpsring that each female has in a generation
Bx=
Number of individuals born between age classes
mx=
Fecundity= average number of female offspring that each female will have at age x
lx=
survivorship= Proportion of individuals that survive from birth (N0) to age x
Nx=
number of individuals at age x
Increasing growth rate in demography structure diagram
wide base (underdeveloped countries)
Decreasing growth rate in demography structure diagram
skinny base
Population growing
Geometric
lamba > 1
Exponential
r > 0
Population stable
Geometric
lamba = 1
Exponential
r = 0
Population shrinking
Geometric
lamba < 1
Exponential
r < 0
Geometric growth has what type of breeding season
Pulsed
Exponential growth has
continuous breeding
Describe types of interspecific interactions based on their effect on each species involved
Competition - -
Exploitation (pred/prey) - +
Mutualism + +
Commensalism + 0
Differentiate among the different types of competition
Intraspecific competitions are within community
Interspecific competitions are between different species
Interference competition is direct antagonistic (pred/prey, 2 kids and 1 straw)
Resource competition is indirect (individual organisms reduce the supply of a common resources, 2 kids 2 straw)
Competitive exclusion principle
If 2 species have the same niche, then one species will eliminate or exclude the other
Partitioning of niches reduces
competition between species and can promote coexistence
Types of niche partitioning
Resource, spatial, temporal
Competition will lead to which 2 outcomes?
Coexistence (1 species feeds on ground seed, other from tree seed) or competitive exclusion (1 species outcompetes the other)
Higher population counts give
higher competitive advantage
Niche
Combination of environmental factors that affect survival, growth and reproduction of a species
Fundamental niche
Suite of abiotic factors and resources where an organism can theoretically live
Realized niche
Subset of the fundamental niche that is actually occupied (determined by biotic interactions)
alpha(1 2)
Effect of species 2 on 1
alpha (2 1)
Effect of species 1 on 2
L-V model
Comp coefficients measure the impact one species has on the growth of another (competing for shared resources)
If competition coefficient is greater than L-v model,
comp species (2) has a larger effect against 1 (strong comp)
If competition coefficient is less than L-V model
comp species (2 for 2) has a smaller effect than an individual of the same species (weak competition)
Predation
Predator/prey exploitation interaction
Parasitism
Pathogen, parasites live on another organism(host) (exploitation interaction)
Parasitoid
Reproductive exploitation
Lay eggs inside host, eventually kills host
exploitation
Herbivory
Eating producers (plants)
Exploitation
aNP for prey
Prey consumption rate
a
search efficiency
r=
prey growth rate
m
rate at which predators die
mp
predator deaths
b
efficiency of biomass conversion
anP for predator
number of new predator babies produced
P
predator number
Describe the oscillating cycle of predator/prey
Prey inc, pred inc, predators overconsume, prey decrease, pred decline
Ecto
external
One partner lives outside the other (fish cleaning shark)
Endo
Lives inside (Gut bacteria in humans)
Facultative
Symbiotic organisms can live seperately
Obligate
Member of the symbiotic relationship cannot live without the other
Explain how variable degree of reliance on a facultative partner might influence the strength of the evolutionary partnership
Low reliance (weak dependence) -> species gains benefit but can easily find alternatives
High reliance (near obligation) -> species depend heavily on another for survival, though interaction is still facultative
Food chains represent
paths of energy flow through different feeding levels within a food web
The more a species relies on a facultative partner, the stronger
the evolutionary relationship
Food webs
show all energy possible (not just 1 direct pathway of energy like food chains)
Consumers influence primary production through
top-down controls
affects lower trophic levels
Producers cause
bottom up effects because changes the amount of biomass available on the bottom of a food chain
affects density of organisms in higher trophic levels and number of trophic levels
Keystone species
influence community structure and function despite their low biomass (more drastic change if removed)
If photosynthesis > respiration
net gain of biomass (growth) (DAY)
If respiration > photosynthesis
consumes more glucose than it produces, so net loss in biomass (NIGHT)
During daylight, both photosynthesis and
respiration occur
AT NIGHT, only ___ occurs in plants
respiration
GPP
Energy from photosynthesis
NPP
Plant biomass left over for consumers to eat (energy stored in chem bonds) (# of energy left after plants use some GPP for resp)
GPP captures solar energy and NPP represents
fraction of that energy stored
Terrestrial primary production
Generally limited by temp and moisture; & nutrient availability and sunlight
Terrestrial NPP is highest in and least in
tropics, tundra (cold and short growing season)
Terrestrial NPP declines with
increasing latitude
How forest age affects NPP
NPP initially increases, then declines with forest age
Low at first bc resources are allocated to establishing roots
b/c more energy is used for maintenance respiration of large biomass
As trees age, growth slows
Calculate the amount of energy (hint: Eltonian Pyramids)available at different levels in a food chain, determining how that varies for organisms that feed at multiple trophic levels
around 10%, so limits the length of food chain
Different reasons that energy among trophic levels are inefficient
Heat loss, energy from maintenance, incomplete consumption
Grassland
upright pyramids
Forest
biomass and energy upright but numbers inverted
Marine
energy always upright, biomass inverted due to fact producer turnover
Summarize the general factors that affect decomposition rates
Temp and moisture
Warmer temp speeds decomp
Too much moisture, reduces O, but moderate moisture speeds decomp
Compare/contrast components of different decomposition mass loss curves with one another
Rapid mass loss early on
Fast initial decomp, then slow phase
Cellulose
Long chains of glucose, decomposes fairly quickly but slower than sugars
Hemicellulose
Branches and less ordered than cellulose, so it decomposes faster
Lignin
Very resistant to decomp; only fungi can degrade it
Warm, wet climates have
rapid decomposition
Cold, dry has slower
decomp
Litter with high lignin
Slower decomp curve, mass loss occurring gradually
Litter rich in cellulose or hemicellulose
Faster early mass loss compared to lignin-rich litter
NEP is negative
night time
GPP > Re
DAy time
GPP=0
Night time
gamma diversity (y)
Number of species in a broader geographic region such as a local community, a continent
Species turnover or beta diversity
describes the change in species composition that occurs over relatively short distances (ie. between sites)
Species accumulation curves plot the
cumulative number of species observed against an index of sampling effort, can be used to estimate alpha diversity
A successful life history produces
stable or growing populations
Birth and death rates are the
number of per capita births and deaths in a specified amount of time
Fecundity
average number of offspring per reproductive female per unit time
Per capita population growth rate
r= b-d
Life table data can be used to
make predictions about future population change
When a population is growing,
R0 > 1 and r >0
When a population is shrinking
R0 < 1 , r<0
Fundamental niche
complete set of conditions under which an organism could potentially survive and reproduce
Realized niche
Subset of the fundamental niche describing the conditions, under which an organism actually lives, given limitations created by interactions with other species
Competitive exclusion principle
no two species can coexist in exactly the same niche
Allelopathy
Occurs when plants release chemicals that inhibit the growth of their competitors
Territoriality
Describes the establishment by an organism or group of a defended area
Preemption occurs when individuals
prevent others from using a location by occupying it first
Density dependent factors
include disease and food shortages
Density-independent factors include
catastrophic weather events
When a population grows, finite resources will become increasingly limited and individuals within the population
compete more stronger with each other for these resources
Predator growth is determined by their
consumption rate, their conversion rate, and their mortality rate
Trophic cascades occur when
predators indirectly limit the size of a population that they are not directly feeding upon
Traditional trophic cascades occur when
predator limits herbivore populations, reducing the effects of herbivory and allowing plant pops to expand
Autogenic engineer
Alter environments through their physical structure (trees provide shade)
Allogenic engineers
Alter environments through structures they build (beavers)
Ecosystem engineers indirectly affect
community dynamics by modifying the environment and thus altering resource availability
Behavioral trophic cascade occur when predators alter the
behavior of herbivores (reducing grazing pressure and benefiting plant pops)
High quality litter decomposes at a
faster rate than low quality
High quality litter has a high proportion of
cellulose, simple carbs, rich in essential nutrients like nitrogen or phosphorus
Low quality litter includes organic matter with high concentrations like
lignin
